# Overview

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Block Storage is a redundant and distributed block device implementation for
Exoscale Compute instances which provides rapid data access and retrieval to
support your most demanding workloads with exceptional performance for
latency-sensitive applications. Effortlessly meeting growing storage demands,
and easily store containerized applications.

High Data Durability
: Multiple data copies are maintained at all times on separate servers.
  Snapshots are retained indefinitely.

Ultra-Low Latency for High-Performance Workloads
: Experience outstanding performance fueled by the latest generation NVMe
  SSDs—ideal for latency-sensitive applications such as databases.

Flexible Storage Capabilities
: Add volumes to your instances anytime, enabling you to scale capacity as your
  needs evolve seamlessly.

## Terminology

Volume
: A single storage device that is partitioned and formatted to store
  directories and files.

Snapshot
: A storage snapshot is the state of a volume at a particular point in time. It
  provides the ability to create new volumes with the state of the current
  volume at that specific point in time.

## Features

Block Storage volumes feature a fixed 4KiB block size and replicate data at
least twice within the same Zone for durability. They support
snapshots—enabling the creation of new volumes (“forking”)—though exporting or
downloading snapshots is impossible. Access is _ReadWriteOnce_, allowing only
a single instance to attach a volume at any given time; however, volumes can be
detached from one instance and reattached to another within the same Zone.

IOPS
: Enjoy 5,000 IOPS per volume for read and write operations—no sharing
  involved.

Built-In Feature
: Use Block Storage alongside Compute Instances or Managed Kubernetes.

Easy Snapshots
: Take a snapshot of any volume via an API call. Create new volumes from
  snapshots whenever needed.

Five Volumes per Instance
: You can attach up to five Block Storage volumes to each instance, with
  a maximum capacity of 10 TiB per volume.

Easy Scaling
: Create a Block Storage volume in seconds using the Exoscale Portal, CLI, API,
  or Terraform provider. Detach and reattach volumes to move them between
  Instances.

Exoscale CSI Driver
: Interact seamlessly with Block Storage from Kubernetes using our Exoscale CSI
  Driver. (Read more)

Two-Times Replication
: Data is replicated twice across multiple nodes, ensuring availability even if
  a disk fails.

Secure Data Storage in Europe
: As a fully European cloud provider, all data remains in your chosen zone and
  is fully GDPR-compliant.

Encryption at Rest
: Block Storage volumes are transparently encrypted using AES-256 in XTS mode
  at the hypervisor layer, with a unique key per volume and no configuration
  required. Snapshots inherit the data encryption of their parent volume. 

With its unique features, Block Storage suits mission-critical, I/O-intensive
applications. Use it for relational and transactional databases, time series,
container volumes, or hypervisor file systems. Because volumes are directly
connected to an instance, their I/O speeds are often significantly faster than
alternative storage solutions like Object Storage.

Flexibility for Containerized Applications
: As containers are flexible, scalable, and efficient, so is our Block Storage.
  Containers benefit from Block Storage’s speed and the native ability to mount
  multiple volumes on a single host. Migrate seamlessly between servers,
  locations, and operating systems.

Discover the Best Cost-to-Performance Ratio
: Our Block Storage offers a fair and transparent cost-to-performance ratio.
  With a simple pricing structure, you’ll have predictable monthly expenses—no
  cumbersome IOPS provisioning or pay-per-use variability.

Persistent Volumes
: Create persistent volumes for critical information, databases, or other
  essential data to retain it over extended periods. These volumes can be